diff --git a/app/main/forms.py b/app/main/forms.py
index 17d1e1a20..f04216993 100644
--- a/app/main/forms.py
+++ b/app/main/forms.py
@@ -1387,24 +1387,6 @@ class ChooseTimeForm(StripWhitespaceForm):
     )
 
 
-class ChooseBroadcastDurationForm(StripWhitespaceForm):
-
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.finishes_at.choices = [
-            get_time_value_and_label(hour) for hour in get_next_hours_until(
-                get_furthest_possible_scheduled_time()
-            )
-        ]
-        self.finishes_at.categories = get_next_days_until(
-            get_furthest_possible_scheduled_time()
-        )
-
-    finishes_at = RadioField(
-        'End time',
-    )
-
-
 class CreateKeyForm(StripWhitespaceForm):
     def __init__(self, existing_keys, *args, **kwargs):
         self.existing_key_names = [
diff --git a/app/main/views/broadcast.py b/app/main/views/broadcast.py
index 025939f4c..d27f14c25 100644
--- a/app/main/views/broadcast.py
+++ b/app/main/views/broadcast.py
@@ -13,7 +13,6 @@ from app.main import main
 from app.main.forms import (
     BroadcastAreaForm,
     BroadcastAreaFormWithSelectAll,
-    ChooseBroadcastDurationForm,
     SearchByNameForm,
 )
 from app.models.broadcast_message import BroadcastMessage, BroadcastMessages
@@ -211,10 +210,8 @@ def preview_broadcast_message(service_id, broadcast_message_id):
         broadcast_message_id,
         service_id=current_service.id,
     )
-    form = ChooseBroadcastDurationForm()
-
-    if form.validate_on_submit():
-        broadcast_message.request_approval(until=form.finishes_at.data)
+    if request.method == 'POST':
+        broadcast_message.request_approval()
         return redirect(url_for(
             '.view_broadcast_message',
             service_id=current_service.id,
@@ -224,7 +221,6 @@ def preview_broadcast_message(service_id, broadcast_message_id):
     return render_template(
         'views/broadcast/preview-message.html',
         broadcast_message=broadcast_message,
-        form=form,
     )
 
 
diff --git a/app/models/broadcast_message.py b/app/models/broadcast_message.py
index 0422fc077..769e36ebb 100644
--- a/app/models/broadcast_message.py
+++ b/app/models/broadcast_message.py
@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 
 from notifications_utils.template import BroadcastPreviewTemplate
 from orderedset import OrderedSet
@@ -153,15 +153,15 @@ class BroadcastMessage(JSONModel):
             data=kwargs,
         )
 
-    def request_approval(self, until):
-        self._update(
-            finishes_at=until,
-        )
+    def request_approval(self):
         self._set_status_to('pending-approval')
 
     def approve_broadcast(self):
         self._update(
             starts_at=datetime.utcnow().isoformat(),
+            finishes_at=(
+                datetime.utcnow() + timedelta(hours=23, minutes=59)
+            ).isoformat(),
         )
         self._set_status_to('broadcasting')
 
diff --git a/app/templates/views/broadcast/preview-message.html b/app/templates/views/broadcast/preview-message.html
index 70a196078..fd8f51f65 100644
--- a/app/templates/views/broadcast/preview-message.html
+++ b/app/templates/views/broadcast/preview-message.html
@@ -29,17 +29,6 @@
   {{ broadcast_message.template|string }}
 
   {% call form_wrapper() %}
-    <h3 class="govuk-heading-s govuk-!-margin-top-6 govuk-!-margin-bottom-1">
-      Start time
-    </h3>
-    <p class="govuk-body govuk-!-margin-bottom-4">
-      Your broadcast will start when it’s approved by another member of your team.
-    </p>
-    {{ radio_select(
-      form.finishes_at,
-      show_now_as_default=False,
-      bold_legend=True
-    ) }}
     {{ page_footer('Submit for approval') }}
   {% endcall %}
 
diff --git a/tests/app/main/views/test_broadcast.py b/tests/app/main/views/test_broadcast.py
index c8bbeb2e1..a6a610456 100644
--- a/tests/app/main/views/test_broadcast.py
+++ b/tests/app/main/views/test_broadcast.py
@@ -532,29 +532,12 @@ def test_remove_broadcast_area_page(
     )
 
 
-@pytest.mark.parametrize('end_time', (
-
-    # Before now
-    pytest.param('2020-02-02T02:00:00', marks=pytest.mark.xfail),
-
-    # End of the current hour
-    pytest.param('2020-02-02T03:00:00'),
-
-    # Midnight 3 days ahead
-    pytest.param('2020-02-06T00:00:00'),
-
-    # 1am 4 days ahead
-    pytest.param('2020-02-06T01:00:00', marks=pytest.mark.xfail),
-
-))
-@freeze_time('2020-02-02 02:02:02')
 def test_preview_broadcast_message_page(
     client_request,
     service_one,
     mock_get_draft_broadcast_message,
     mock_get_broadcast_template,
     fake_uuid,
-    end_time,
 ):
     service_one['permissions'] += ['broadcast']
 
@@ -582,47 +565,21 @@ def test_preview_broadcast_message_page(
     assert form['method'] == 'post'
     assert 'action' not in form
 
-    radio_choices = [
-        choice['value'] for choice in form.select('input[type=radio][name=finishes_at]')
-    ]
-    assert len(radio_choices) == 94
-    assert end_time in radio_choices
 
-
-@pytest.mark.parametrize('end_time', (
-
-    # Before now
-    pytest.param('2020-02-02T02:00:00', marks=pytest.mark.xfail),
-
-    # End of the current hour
-    pytest.param('2020-02-02T03:00:00'),
-
-    # Midnight 3 days ahead
-    pytest.param('2020-02-06T00:00:00'),
-
-    # 1am 4 days ahead
-    pytest.param('2020-02-06T01:00:00', marks=pytest.mark.xfail),
-
-))
 @freeze_time('2020-02-02 02:02:02')
 def test_start_broadcasting(
     client_request,
     service_one,
     mock_get_draft_broadcast_message,
     mock_get_broadcast_template,
-    mock_update_broadcast_message,
     mock_update_broadcast_message_status,
     fake_uuid,
-    end_time,
 ):
     service_one['permissions'] += ['broadcast']
     client_request.post(
         '.preview_broadcast_message',
         service_id=SERVICE_ONE_ID,
         broadcast_message_id=fake_uuid,
-        _data={
-            'finishes_at': end_time,
-        },
         _expected_redirect=url_for(
             'main.view_broadcast_message',
             service_id=SERVICE_ONE_ID,
@@ -630,13 +587,6 @@ def test_start_broadcasting(
             _external=True,
         ),
     ),
-    mock_update_broadcast_message.assert_called_once_with(
-        service_id=SERVICE_ONE_ID,
-        broadcast_message_id=fake_uuid,
-        data={
-            'finishes_at': end_time,
-        },
-    )
     mock_update_broadcast_message_status.assert_called_once_with(
         'pending-approval',
         service_id=SERVICE_ONE_ID,
@@ -644,32 +594,6 @@ def test_start_broadcasting(
     )
 
 
-def test_start_broadcasting_shows_validation_error(
-    client_request,
-    service_one,
-    mock_get_draft_broadcast_message,
-    mock_get_broadcast_template,
-    mock_update_broadcast_message,
-    mock_update_broadcast_message_status,
-    fake_uuid,
-):
-    service_one['permissions'] += ['broadcast']
-    page = client_request.post(
-        '.preview_broadcast_message',
-        service_id=SERVICE_ONE_ID,
-        broadcast_message_id=fake_uuid,
-        _data={},
-        _expected_status=200,
-    )
-    assert mock_update_broadcast_message.called is False
-    assert mock_update_broadcast_message_status.called is False
-    assert normalize_spaces(
-        page.select_one('form fieldset legend .error-message').text
-    ) == (
-        'Select an option'
-    )
-
-
 @pytest.mark.parametrize('extra_fields, expected_paragraphs', (
     ({
         'status': 'broadcasting',
@@ -945,6 +869,7 @@ def test_approve_broadcast(
             broadcast_message_id=fake_uuid,
             data={
                 'starts_at': '2020-02-22T22:22:22',
+                'finishes_at': '2020-02-23T22:21:22',
             },
         )
         mock_update_broadcast_message_status.assert_called_once_with(